AB1044 SELF-REPORTED HIDRADENITIS SUPPURATIVA-LIKE SKIN SYMPTOMS IN PATIENTS WITH SPONDYLOARTHRITIS: RESULTS FROM AN ONLINE SURVEY
Authors: A. Spoorenberg, M. Kim, I. Pansar, H. Lapidus Glassner
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Hidradenitis suppurativa (HS) is a chronic immune-mediated disease with known associations with other chronic auto-inflammatory diseases, such as inflammatory bowel disease and spondyloarthritis (SpA).<sup>[1–3]</sup> However, real-world data on the occurrence of HS in patients with SpA are limited. <h3>Objectives</h3> To explore the proportion of patients with SpA who report having an HS diagnosis from a doctor or report having undiagnosed skin symptoms similar to HS. <h3>Methods</h3> An online survey with validated questions about HS diagnoses/symptoms was conducted from 1–22 September 2021 among users of the social network MySpondylitisTeam, aged ≥21 years and reporting a SpA diagnosis (principally ankylosing spondylitis [AS; also known as radiographic axial spondyloarthritis], non-radiographic axial spondyloarthritis [nr-axSpA], or psoriatic arthritis [PsA]), or a SpA diagnosis but without knowing the specific subtype.<sup>[1]</sup> Prototypical pictures of HS symptoms were included to help participants identify these symptoms. <h3>Results</h3> 369/448 participants with self-reported SpA diagnoses completed the full survey; 81% were female, 69% aged 50–70 years and most from the US (87%; with a further 8% from the UK and 2% from Canada). While most participants reported that a doctor had diagnosed them with one SpA subtype, others reported diagnoses of &gt;1 SpA subtype, potentially reflecting symptom overlap with different SpA subtypes (SpA symptom overlap) (<b>Figure 1</b>). Three percent (12/369) of participants reported an existing HS diagnosis; of the remaining 357 participants without an HS diagnosis, 18% (65/357) self-reported skin symptoms resembling HS. Among the principal SpA subtypes studied, an HS diagnosis was most frequent among participants with PsA (8%; 3/38), while undiagnosed HS-like skin symptoms were reported by 11% (4/35) of the participants with PsA who did not report an HS diagnosis. All participants with PsA and either an HS diagnosis or undiagnosed HS-like skin symptoms also reported having SpA symptom overlap (<b>Figure 1</b>). The participants with nr-axSpA exhibited the highest proportion of undiagnosed HS-like skin symptoms (29%; 10/35, including participants reporting SpA symptom overlap) while very low rates of HS diagnoses were reported (<b>Figure 1</b>). Among those reporting undiagnosed HS-like skin symptoms (or unsure if they have them), 48% (34/71) had previously discussed their skin symptoms with a healthcare professional. These participants mainly reported being told that their skin symptoms were due to infected hair follicles (44%; 15/34) or cysts (24%; 8/34). <h3>Conclusion</h3> Of the participants surveyed, very few reported an HS diagnosis while a considerably higher proportion reported skin symptoms resembling HS. Despite the limitations and potential biases inherent in online surveys, these results suggest that HS may be underdiagnosed in patients with SpA and highlight a need for further research and potentially, greater awareness of HS in the clinical care of patients with SpA. <h3>Reference</h3> [1]Rondags A. Semin Arthritis Rheum 2019;48:611–7; <b>2.</b> Almuhanna N. Dermatology 2021;237:740-7; <b>3.</b> Deckers I.E. J Am Acad Dermatol 2015;72:485–8. <h3>Acknowledgements</h3> This study was conducted by MyHealthTeam and funded by UCB Pharma. Medical writing support was provided by Costello Medical, funded by UCB Pharma. The authors thank Barbara Horváth for her contribution to this work, including survey question formulation and analysis of the survey data. <h3>Disclosure of Interests</h3> Anneke Spoorenberg Consultant of: Abbvie, Eli Lilly, MSD, Novartis, Pfizer and UCB Pharma, Grant/research support from: Abbvie, Novartis, Pfizer, UCB Pharma, Mindy Kim Shareholder of: UCB, Employee of: UCB Pharma, Ingrid Pansar Shareholder of: UCB, Employee of: UCB Pharma, Heather Lapidus Glassner Grant/research support from: Employee of MyHealthTeam, which received funding from UCB Pharma to conduct studies on the impact of HS.